Mazda quietly released a new rotary engine when nobody was paying attention

This might look like a regular Mazda CX-30 but if you have been following Mazda’s recent activities, you will know by now that any Mazda with a matt black paint and contrast colour side mirrors is a prototype that is hiding something important underneath the familiar looking body.

It’s Mazda’s way of having a little bit of fun while leaving some Easter eggs for sharp-eyed enthusiasts to spot. The company did this with the all-new Mazda 3 SkyActiv-X, whose running gear was first presented to the world using the previous Mazda 3’s body.

Since the rotary engine-powered RX-8 was discontinued in 2012, Mazda fans from around the world have been asking when Mazda will make a new rotary engine.

Rotary engines have been synonymous with Mazda since the late ‘60s, when the first generation Cosmo was introduced.

Mazda remains the only company to successfully realize Dr. Felix Wankel’s rotary engine design. It’s also the only Asian company to have won the Le Mans 24 Hours, and Mazda did it with a rotary-powered 787B.

However tightening emissions regulations and the rotary engine’s inherent weakness in thermodynamic efficiency also means it is no longer possible to make a rotary engine-powered car today.

While acknowledging the challenges in making a rotary engine that’s clean enough to meet today’s regulatory climate, Mazda have repeatedly said that it hasn’t given up on rotary engines, even as piston-type SkyActiv engines take priority.

Earlier last week, Mazda had quietly announced this electric-powered CX-30 e-TPV (Electric Technology Prove-Out Vehicle) prototype. It was a European affair that took place in Oslo and news of the announcement didn’t get much coverage outside of Europe.

From the outside, the CX-30 e-TPV looked like a regular combustion engine model. Underneath it however, is an electric powertrain. Mazda has said before that it plans to introduce its first battery electric vehicle by 2021.

This CX-30 e-TPV will most likely preview that model, and it’s equally likely that the electric drivetrain will appear in a Mazda 3 or something else (Mazda did stress that the body chosen for the prototype doesn’t signify anything).

However unlike a Tesla or a Nissan Leaf, the CX-30 e-TPV is not a Battery Electric Vehicle (BEV). Instead, this is a REEV (Range Extended Electric Vehicle), like a Chevrolet Bolt, or a BMW i3 equipped with the optional 650cc two-cylinder engine in the rear.

REEVs are not a popular option for manufacturers because customers find it confusing to understand it actually is. It was the reason why the Chevrolet Bolt failed in USA while the Nissan Leaf pulled ahead.

A REEV has an engine but it’s not a hybrid because the engine doesn’t drive the wheels. However unlike a BEV, it also has an engine which needs minimal maintenance.

BMW was smart enough to simplify the i3’s marketing to portray it as a BEV-type electric car, even though 50 percent of European buyers opted for the 650cc range extender engine option.

However, REEVs make perfect sense because the tiny engine serves as backup generator in the event that you run out of charge. Think of it as an electric vehicle that carries its own generator.

The tiny engine doesn’t power the car, but merely acts as a generator so it can be designed to be very small, and run at a constant rpm for maximum efficiency.

As for this CX-30 e-TPV, well the range extender engine chosen is a rotary-type unit. It makes perfect sense. While rotaries might not be good enough to power today’s cars, it’s compact and lightweight packaging makes it a perfect choice as a secondary motor.

Details are still lacking as Mazda’s official announcement only say that it has a rotary range extender and that the model will premiere at October’s opening of the 2019 Tokyo Motor Show.

Reports from the European press say that the CX-30 e-TPV uses a small 35.5 kWh floor-mounted lithium-ion battery pack. That’s slightly smaller than the Nissan Leaf’s 40 kWh pack but remember that the CX-30 is also slightly larger.

Mazda believes that this combination is optimal because batteries are heavier than a lightweight and compact rotary-engine, and this combination yields the best driving experience.

We will share more details when we find out more about that car at next month’s Tokyo Motor Show.